Damping system for musical instruments.



G. B. SINCLAIR & M. L. SEVERY.

DAMPING SYSTEM FOR MUSICAL INSTRUMENTS.

APPLICATION HLED JULY 21,1910.

Patented May'16,1916.

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DAMPING SYSTEM FOR MUSICAL INSTRUMENTS.

APPLICATION FILED JULY 2I, I9I0.

1 ,1 83,685 Patented May 16, 1916.

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Geo rye B. S 521011150" 3 QWLVAZ UNITED STATES PATENT onrion GEORGE B. SINCLAIR, OF MEDFORD, AND MELVIN L. SEVEBY, OFARL-ING-TON HEIGHTS.

MASSACHUSETTS, ASSIGNORS TO CHORALCELO COMPANY, OF BOSTON, MASSACHU- SETTS, A CORPORATION OF MAINE.

. DAMPING SYSTEM non. MUSICAL ms'rnumnnrs.

Specification of Letters Patent. 4 Patented 1113.5 16, 1916 ,Application filed July 21, 1910. Serial Nos- 573,135. i

To all whom it may concern: 1 I

Be it known that we, GEORGE B. SINCLAIR, of Medford, and MELVIN L. SEVERY, of An lington Heights, in the county of Middlesex and Commonwealth of Massachusetts, both citizens of the United States, have invented certain new and useful Improvements in Damping Systems for Musical Instruments, of which the following is a specification.

This invention relates more especially to that class of musical instruments wherein sonorous bodies, and particularly" tuned strings, are vibrated either by means of hammers, or by electromagnets receiving properly-timed electric pulsations, or by means of both, as set forth incur companion applications Serial Nos. 273,199 and 745,400.

One of the especial purposes of this invention is the construction of electrically controlled means whereby a plurality of dampers may be applied to a single string and all simultaneously withdrawn from such string upon the depression of the key or the operation of the'parts of the action associated with said string. In actual practice, we prefer two dampers for each of the lower,

or bass, strings of the instrument, one dam-- per being located normally to damp the string at a point as close as possible to where it is struck by its hammer, and the other damper being preferably located at a point equally distant from the other end of the string.

In certain co-pending applications we have shown, described and claimed, features which are illustrated and} described in the present application, but which are not herein claimed, and in other co-pending applications we have broadly claimedthe art ofproducing musical tones, which art is in volved but not claimed in the present application. All matters set forth and claimed in co-pending applications filed in our names, or in the name of either of us, and not specifically claimed herein, are expressly saved and. reserved for one or another ofsuch applications. Among these may be noted our joint applications Serial No. 273,199, filed August 7, 1905; Serial No. 379,714, filed June 19, 1907; Serial No. 531,589, filed December 6, 1909; Serial No. 537,257, filed January 10, 1910; and Serial No. 745,400, filed January 31, 1913.

Referring to. the drawings forming part of this specification, Figure 1 is a perspective view, 'more or less in diagram, of a musical instrument embodying our invention. Fig. 2 isj aside sectional elevation of.

the auxiliary dampers, the same being shown plied, are of iron, steel or other magnetically attractive material, and are vibrated by means of electromagnets 2 to which electric pulsations are transmitted. The cur rent for such purpose is received from the source'3 through the pulsator consisting of the toothed rings 4 and brushes 5; and the circuit for the same comprises the wire 6, brush 7, toothed rings 4, brushes 5, wires 9, to said electromagnets '2, and from thence through the wires 10 to the action rail 11, resistance 12, contacts 13, 14, brushes 15 and Wire 16 back to said source.

Each key 17 by its depression at its outer end elevates a sticker 19, and by the latters engagement with the action of an associated hammer 20 throws said hammer percussively against a string 1. Each sticker is pivotally connected to a lever extension 21 at the free end of which is one of said brushes 15, whereby the depression of a key moves its brush 15-up into touch with the associated contact 13, "thereby switching a limited amount of current to an electromagnet 2, such limitation being due to said resistance 12; and then such brush rises into touch with the upper associated contact 14 and so delivers full current to such electromagnet.

As thus far described, the actuation of a key delivers both a percussive and also an electromagnetic set of vibrations to its associated string. To permit the depression of the keys to electrically vibrate the strings without the percussive action, the upper ends of the stickers 19 are adapted to be withdrawn from engagement with the wippens 29, as more fully set forth in our Patent No.

1,104,282, dated July 21, 1914.

The dampers 25 are pivotally supported near the electromagnets 2, and each is withdrawn from its associated string or strings by means of a spoon 26 rising from a lever arm 27. Each arm 27 is pivoted to a wippen' 29, as shown in Figs. 1 and 4, in such a manner asto permit the several'arms of the series to be freely depressed without affecting their respective wippens, while the movement of said wippens in actuating the hammers will force said arms downwardat every actuation. Any such depression of the lever arms 27 causes, by the consequent pressure of the spoons 26 against the tails 30 of the dampers, theremoval of'the associated dampers from their strings.

Each lever arm 27 is connected by a link 31 to an armature 32 pivotally supported 'just above an electro-magnet 33, of which undamping to be performed mechanically when the electrical actuation of the strings is switched ofi; and enables the undamping to be performed electrically when the stickers 19 are withdrawn from engagement with the hammer action and the instrument is being played electrically.

Each electromagnet 33 is wired to the Iproper contacts 13, 14 as by the wire 34, and y a common lead wire 35 to said source of current 3. Hence the circuits to said electromagnets and to the electromagnets'2 have each a common section comprising a brush vibrating 15, contacts 13, 14 and resistance 12; and accordingly, upon the closing of a circuit for delivering. ulsatory currents to a stringelectromagnet, the circuit is simultaneously closed by which non-pulsatory currents are delivered to the undamping electromagnets.

In addition to the dampers 25 above described, a considerable number of the lower bass strings are each provided with a damper 40 'located near the lower end of the string, as shown in Fig. 1, the construction of each such damper being shown upon a larger scale in Figs. 2 and 3. Here it will be seen that the damper-felts are held by a short bar 41 carried by a wire 42, the latter being held by the bell-crank lever 43 which is pivotally supported at 44. A spring 37 keeps the damper in normal contact with its associated string 1, while an electromagnet 45 acts upon a pivoted armature 46 connected by a link 47 to the short arm of said lever. Each said electromagnet 45 is connected by a wire 48 to its proper contact 14 as by having said wire 48 joined to a wire 10, and is also wired to the current-source 3, asby means of. the leads 49, 35. See Fig. 1.

The magnets and contacts being thus wired, it follows that whenever a key 17 is depressed or. the parts of the action associated therewith are operated, and its associated brush 15 is brought into engagement 1 with a contact 14, a pulsatory current flows to the associated electromagnet 2, and nonpulsatory currents pass to the connected electromagnets 33 and 45. The dampers 25 and 40 will hence be immediately withdrawn by the-magnets 33 and 45 from the string controlled by the actuated key, and saidstring will be electrically vibrated by the magnet 2.

Inasmuch as 'it is necessary to cut away a part of the sounding board 50 in order to makeroom 'for the electromagnets 2, while the lower part of the sounding board can be run direct to the bridge supporting the ends of the strings thereat, the lower ends of the strings consequently have a more pronounced sonorous effect upon-the sounding board than their upper ends. For this reason, the auxiliary dampers 40 are more efficient in terminating the sonorous effect of the vibrations of their strings than are the upper dampers 25. In instruments where only the ordinary upper dampers are used, the undamped longer sections of the strings may continue to vibrate for an appreciable time after the seating of the dampers, and affect the sounding board through the direct' connection oftheir lower ends therewith. But when the lower tier of dampers. is used, the strings are instantly damped at their points of connection with the sounding board, and all sound therefrom promptly terminated. This com lete termination is made more certain by the joint employment of two dampers for each' of the heavier bass strings.

Another advantage inherent with these auxiliary dampers is that they may be lo cated at exactly the proper; places on their strings, whereas the upper dampers must accommodate the hammers. Again, sufficiently strong springs 37 can be used for the auxiliary dampers to properly damp their strings, since these dampers are withdrawn by electromagnetic means entirely and the latter can be made as powerful as needed. The upper dampers, on the other,

hand, must not be given springs stronger than the key-controlled actions will allow.

The auxiliary dampers are'all withdrawn from their strings by means of a suitable pedal (not shown) acting through a bar 51 (Fig. 2) pivotally supported at 52 and swung forward .against the bell crank levers 43 by. pressure .against the arm 53, in sub-- stantially the usual manner.

It will be seen from the foregoing description that in the embodiment of the invention illustrated, the dampers constitute two sets or tiers, and that the dampers of each tier or set have mechanical means for their withdrawal, the means associated with the dampers of one tier or set being independent of "the means associated with the dampers of the other tier or set.

' It, may happen that, when the heavier bass strings are made to sound their most powerful notes for a considerable interval of time, the vibrations will build up as it is called, and swing through such an ampli-' tude of, vibration as to strike their actuating electromagnets 2. To prevent this, we prefer to locate behind the strings near their lower ends a board 55 having on its face a sheet of soft material 56 which is met by the strings whenever they exceed a suitablysafe amplitude of vibration. This board is not for the purpose of affecting the vibra tions in any other way, but is simply intended to restrain them from passing a safe amplitude.

Owing to the limited space between the strings, the magnets 33' of the upper series are arranged in two rows or tiers and in staggered relation, so that the magnets of one tier alternate with those of the other, and the links 47 connecting the armatures C6 of the lower tier with the levers 43, pass between the magnets and armatures of the upper tier. The same arrangement is for the like reason adopted for the lower magnets 45, and is clearly shown in Fig. 3. This Fig. 3 also illustrates another feature in' regard to the auxiliary dampers. As will be evident upon inspection, the levers 43 increase in length toward the right, the shortest lever acting to damp the lowest bass string,and the longer ones serving for those progressively higher in pitch. The impressing springs 37, on the other hand, are shown-of the same length for all the levers. The purpose is this: The springs being all of the same'strength, the pressure therefrom on the shortest lever comes so points of the leversat a constant level and shorten their lengths as illustrated. Thus this requirement operates in. conjunction with the constant length of the springs to accomplish two distinct functions.

It is obvious that this instrument lends itself most readily to mechanical manipulation by means of traveling perforated music rolls, and the like, as found in the.

mechanical players at present on the market,- most of which operate to press the keys of the ordinary keyboard. Any means, however, of openin and closing the appropriate electrical circuits, whether through the operation of the keys of the keyboard or otherwise, would come well within the scope of our invention, and whenever, therefore, we herein refer to keys we wish to be understood to include within that term any mechanism operating to produce the results for which said keys are designed, as it is manifest' that thevarious circuits of this instrument could be opened and closed mechanically, either with or without the use of a keyboard. We do not, therefore, limit ourselves either in this specification or the claims to an instrument operated only by the usual pressure of the keys of a keyboard, but desire to include any means by which this instrument may be operated by a mechanical or human player.

It is customary in the piano-type of musical instruments to employ either one, two or three strings for a single note, but in-the drawings, for the sake of clearness, but one string is represented for each note. The terms sonorous body, and string are also employed in the specification and vclaims as embracing a note of either one or a plurality of sonorous elements tuned in unison and used as a single note.

What we claim as our invention and for which We desire Letters Patent is as follows, to wit 1. The combination with sonorous bodies tuned to the notes of the musical scale, and

with means for their vibration, of a series of damping devices, one for each of said bodies; a second series of damping devices, one for each of certain of said bodies; mechanical means for operating each of the damping devices of the first series; and electrical means for operating the damping devices of the second series.

2. The combination with sonorous bodies tuned to the notes of the musical scale, and

means for their vibration, of a damping device associated with each of said bodies, a

- ha-m second damping device associated with each of certain of said bodies, mechanical means for operating each of said first-mentioned damping devices independently, mechanical means for operating all of said last-mentioned damping devices simultaneously, and electromagnetic means for withdrawing all of the dampers from a given body simultaneously.

3. The combination with sonorous strings tuned to the notes of the musical scale, of electromagnetic and percussive means for their vibration, dampers arranged to damp each of said strings adjacent the striking point of the percussive means, other dampers located at a point equally distantfrom' the other end of the string, and electromagnetic means for controlling, all of the dampers of each of said strings simultaneously.

4. A musical'instrument comprising -so norous bodies tuned to the notes of the musical scale; a plurality of dampers for each said body in a certain section of said instrument, normally in damping relation thereto,

said dampers being arranged in separate sets same, a damper for each string, an auxil- 40 iary damper for each of certain of the strings located near the other ends thereof, and electromagnetic means controlled by said keys for withdrawing both dampers simultaneously from each of said strings.

6. A musical instrument comprisingtuned sonorous bodies; electromagnetic means for v their vibration including a source of ourrent and circuit-connections; keys controlling said circuit connections; a plurality of mechanically independent dampers for each of certain of said sonorous bodies; and electromagnetic means forming parts of said circuit connections and controlling each source of current and circuit connections-for said electromagnets; a section of-the circuit connections of the damper-electromagnets and of the electromagnetic vibrating means of each sonorous body being common; and a brush associated with each said body for opening and closing the connections at the common section.

8. A musical instrument comprising sonorous bodies tuned to the musical scale; means for vibrating said bodies, comprising an electromagnet and circuit for each such body, and a source of current for said circuits; a rheostat in each circuit; keys controlling said circuits; a plurality of dampers for each sonorous body and individual thereto; and individual electromagnets for said several dampers, each in a branch of the circuit of the magnet'which vibrates said sonorous body.

9. A musical instrumentcomprisingtuned sonorous strings, electrical and percussive means for their vibration, keys controlling their vibration, a damper for each string located close to the point where the latter is struck, an additional damper for each of certain of the strings located near the end thereof farther from its striking point, and means whereby the depression of any key removes from its associated string both dampers contacting therewith.

In testimony that we claim the foregoing invention, we have hereunto set our hands this 11th and 16" days of July, 1910.

GEORGE B. SINCLAIR. MELVIN L. SEVERY.

Witnesses to George B. Sinclair:

IENNETH C. DUNLOP, MARGARET F. SINCLAIR.

Witnesses to Melvin L. Sevcry:

ELIZABETH V. Monnrsox, HAROLD W. RAYMOND. 

